U.S. Pat. No. 4,100,594 describes a headlight of the type defined above in which two shields separated from each other in the direction of the optical axis are provided for reducing or eliminating the phenomenon of iridescence of the light beam. However, the presence of two shields complicates assembly and increases the bulk inside the headlight not only because of the two shields but also the means for holding them relative to the headlight and with respect to each other.
The aim of the invention is in particular to provide a headlight as defined above which, whilst reducing or eliminating the phenomenon of iridescence, is more simple to assemble and has good compactness of the internal parts.